Many machines (e.g., devices) communicate visual information to their users via screens (e.g., light emitting display screens, projector screens, or heads-up displays). As an example of such a machine, a device (e.g., a portable hand-held device) may include a touch-sensitive screen (e.g., a touchscreen) that is configured to both display visual information and detect user input in the form of various touches (e.g., taps, double taps, drags, pinches, and reverse pinches).
In some implementations, a device with a touch-sensitive screen is configured (e.g., programmed) to operate in a locked state or an unlocked state. In the locked state, the device may exclusively display on its screen a “lock screen” that indicates the device is in the locked state and prevents access to any other GUI on the device. Furthermore, the device in the locked state may ignore all user inputs (e.g., touches on the touch-sensitive screen) except a user input that represents a command to exit the locked state and enter the unlocked state of the device (e.g., a tap or drag in a particular portion of the touch-sensitive screen). In entering the unlocked state, the device ceases displaying the lock screen and provides access to (e.g., displays) one or more GUIs available on the device (e.g., for normal operation of the device).